Effects of complete denture wearing on temporomandibular joints: a histomorphometric study.

At autopsy, 54 human temporomandibular joints were distributed in three groups. The first group was made up of 14 joints of dentate subjects (mean age = 51 years). The second group was composed of 12 temporomandibular joints of totally edentulous patients who had lost their teeth for at least 10 years (mean age = 82 years). The third group was composed of 28 joints of edentulous patients who had been wearing complete dentures for at least 20 years (mean age = 66 years). Sagittal serial decalcified sections were studied by light microscopy and was submitted to histomorphometry. Group 1 was characterized by a deep mandibular fossa with well-marked cortical layers of the temporal bones and the condyles. The fibrocartilages were multilayered and the articular disks had biconcave outlines. In group 2 a flattening of the mandibular fossa was observed, with a thinning of the cortical and spongy bones. The fibrocartilages were thin and not multilayered. In group 3, the structure of joints was similar to that of group 1. The mean values of the surfaces, thicknesses, and lengths of the measured parameters were systematically highest in group 1, whereas these mean values in group 3 were similar to or had a tendency to be close to the means of group 1. In contrast, the mean values of group 2 were always the lowest. It can be concluded that complete dentures had a favorable protective effect on temporomandibular joint structures.